Difficulty Score: how it works

The headline score

Every marathon on MarathonRoutes is given a difficulty score between 0 and 10, where 0 is pancake-flat and cool, and 10 is a brutal mountain marathon in the heat. The score is a weighted average of six components that account for everything that actually slows a runner down.

The six components

Elevation (30%)

Total elevation gain across the course. Flat courses like Berlin score below 2. Undulating city marathons around 3–5. Mountain marathons above 8.

Hill placement (20%)

Where the climbing happens. Hills in the last third cost far more than hills in the first third — Boston's Heartbreak Hill at mile 20 is the canonical example.

Weather (20%)

Based on 10-year average race-day temperature, humidity and rain probability. Ideal is 8–12°C. Hot + humid compounds fast.

Altitude (10%)

Marathons above 1,500m lose a meaningful amount of aerobic capacity. Most road marathons are at sea level and score 1.

Turns & course shape (10%)

Multi-lap courses with tight corners cost seconds per kilometre. Point-to-point courses with long straight stretches are fastest.

Surface (10%)

Tarmac is baseline. Cobblestones (Rome, Paris segments) and trail sections add difficulty — both on the legs and on the pace.

What the score doesn't include

Crowd support, aesthetics, organisational quality, cutoff generosity, and logistics all matter — but they don't affect how hard it is to physically complete the race. We track those separately in the race page so you can weigh them yourself.

The score is also not a predictor of your personal finish time. It's a relative ranking of courses. Your own fitness, training and pacing decide your actual result.

Updates and feedback

The methodology is versioned. The current version is v1.0. If we improve the scoring we'll rebuild every score and publish the changes here. If you think a particular race's score is off, let us know — we take runner feedback seriously.

See the scores

Browse all marathons by difficulty →